On mission mornings my memory holds the muted sound of the auxiliary power units (APU) from around the field greeting us on arrival at the aircraft. Bombs had been loaded during the night and the 50 cal. gun barrels placed in a neat row on the ground. On opening the nose hatch of the B-17 and pitching in my parachute, bombardier case,two gun barrels,then swinging up into the aircraft a few groans from my added weight were forthcoming. On a damp, cool, misty morning , the odor inside was like that of a museum being opened to the morning fresh air. Other groans, soft voices and a slight movement of the airframe became prominent as crew members completed their pre-flight duties. "Walking through the props" was the next crew assignment. This produced a low growl bearing noise with each revolution of the propellers. With the crew back on board the awaited "start engines" command was received. The first sign of bomber life gushed forth in a belch of black smoke from the exhaust of #3 engine. The sleeping giant was alive and from that moment on became a bee-hive of activity that continued until we returned to the hard stand and shut down the engines.